Sheet igniter

ABSTRACT

1. A holding, launching and ignition device for a plurality of miniature rockets comprising in combination: A. A BLOCK OF FOAM PLASTIC; B. A PLURALITY OF HOLES THROUGH SAID PLASTIC, SAID HOLES EXTENDING FROM A FRONT SURFACE TO A REAR SURFACE OF THE BLOCK; C. A MINIATURE ROCKET HAVING A NOZZLE AT THE AFT END THEREOF IN EACH OF SAID HOLES; D. THE AFT END OF EACH NOZZLE BEING SUBSTANTIALLY FLUSH WITH THE REAR SURFACE OF THE BLOCK; E. A FUSE EXTENDING FROM EACH OF THE ROCKET NOZZLES AND BENT TO LIE FLUSH ON THE SURFACE OF THE BLOCK; F. A THIN PYROTECHNIC LAYER SPREAD OVER SUBSTANTIALLY THE ENTIRE REAR SURFACE OF THE BLOCK; G. SAID PYROTECHNIC LAYER ENCOMPASSING ALL OF THE ROCKET FUSES; AND H. MEANS FOR IGNITING THE PYROTECHNIC LAYER.

I United States Patent 1151 3,702,090

Hoard 1451 Nov. 7, 1972 [54] SHEET IGNITER FOREIGN PATENTS ORAPPLICATIONS Inventor: C a s ard, a a d. Calif- 578,034 6/1959Canada.....................89/l.7 B

[73] Assigneez MB Associates, San Ramon, Cal1f. Primary Examiner samuelw. Engle [22] Filed: Feb. 5, 1965 21 Appl. No.: 433,534 EXEMPLARY CLAIMl. A holding, launching and ignition device for a plu- RelatedAppl'catmn Data rality of miniature rockets comprising in combination:[63] Continuation of Ser. No. 103,289, April 17, a block of foam p 19 1,abandone b. a plurality of holes through said plastic, said holes 7extending from a front surface to a rear surface of [52] us.Cl..................................89/1.813, 89/l.816 the y q 51] Int.Cl. 3/04 a mmlamre rocket havmg a nozzle at the aft end [58] Field ofSearch..............102/49; 206/3; 89/17 B thereof each of Sald holes;

d. the aft end of each nozzle bemg substantlally [56] References Citedflush with the rear surface of the block;

e. a fuse extending from each of the rocket nozzles UNITED STATESPATENTS and bent to lie flush on the surface of the block;

1. a thin pyrotechnic layer spread over substantially the entire rearsurface of the block; g. said pyrotechnic layer encompassing all of the102/34 rocket fuses; and Re et a1 g h. means for igniting thepyrotechnic layer. Loedding.....................102/49 3 Claims, 3Drawing Figures 24,468 6/1859 Lanergan.....................102/34956,546 5/1910 Schulman....................102/33 2,043,268 6/1936Skinner 2,792,962 5/1957 Granfelt................... 2,844,073 7/19582,853,946 9/1958 SHEET IGNITER This application is a continuation of mycopending application Ser. No. 103,289, filed Apr. 17, 1961, nowabandoned, and entitled Sheet Igniter.

This invention relates to a method and apparatus for securing andigniting a plurality of miniature rockets.

Large rockets are fired singly with individual ignition systems; insituations requiring more than one simultaneous firing, the large scaleof said ignition systems permits parallel connection easily. Further, itis not difficult to provide integral attachment points to hold largerockets securely for transportation and handling and the releasemechanism may be complex without adding excessive cost relative to thevalue of the rocket. The miniature rockets to which this inventionrelates are extremely small in size wherein the rocket has a diameter ofabout 1/10 inch and a length of 1% inches. Ordinarily, ignition isaccomplished by means of a defiagrating fuse extending to the rearthrough the nozzle throat. Such miniature rockets are fired in salvosconsisting of large numbers of individual rockets, for example, 100,1,000, 10,000 or more simultaneously. It is obvious that for practicaluse the ignition method must be frugal of material, providesubstantially simultaneous ignition of each rocket and be simple toassemble to a large number of individual rockets.

A method for substantially simultaneous ignition has been devised,suitable for large numbers of miniature rockets supported in a flat orcurved array so that their nozzles occupy points on a plane or curvedsurface. Further, said apparatus for ignition may also provide means forsecuring the miniature rockets for transportation and handling until theinstant of ignition.

It has been found by experiment that a thin sheet material, such asplastic or metal foil, may be coated with a pyrotechnic, which uponignition at any point conducts flame with great rapidity over the wholeof the coated surface. Further, a second thin sheet may be added toconfine the pyro-technic coating between the two and it is well known tothe art that increases in burning rate result upon confinement of apyrotechnic.

Suitable sheet materials include polyethylene film, mylar film,nitrocellulose film and magnesium, aluminum or copper foil. Suitablepyrotechnic compositions include Sb S and Ba(NO boron and KNO aluminumand KClO lead and mononitroresorcinate and KCIO mixed with a smallamount of binder of plastic or nitrocellulose. Said binder may be addedin sufficient percentage to provide a sticky mass with solvent (such asacetone, methyl ethyl ketone, or methyl isobutyl ketone), and to yield afirm cement-like material upon drying. It is this cement-like propertyof the pyrotechnic composition that may be utilized to attach theminiature rockets to their support until the instant of ignition.

In the drawings forming part of this application:

FIG. 1 is a perspective view of a launching device embodying the presentinvention, with certain parts cut away;

FIG. 2 is an enlarged partial sectional view through a rocket chamber ina launching device; and

FIG. 3 is an enlarged perspective view of an ignition sheet.

Turning now to a description of the drawing by reference characters,there is shown a launching device, generally designated 3, which can bemade of a suitable construction material such as a foam plastic 5. Thedevice has a series of channels 7 therin, each of which is adapted toreceive a miniature rocket 9. in carrying out the present invention, inaccordance with one embodiment, a sheet of plastic film or metal foil 1l is placed over the open channels of the launching device 3, and theminiature rockets 9 are then inserted into the channels 7 by passingthem through the sheet 11. This leaves the aft end of the rocket flushwith the sheet 11 with the fuse 13 of the rocket bent over and lyingsubstantially parallel to the sheet 11. The sheet 1 l is then coatedwith a pyrotechnic mixture 15 as has been heretofore described. Thiscoating accomplishes intimate contact with each of the fuses l3 and alsocements the aft ends of the miniature rockets 9 to the sheet 11. A coversheet 17 is then placed over the pyrotechnic mixture 15, which sheet canbe the same or different from the sheet 11. The sheet 11 might be a foilwhile the sheet 17 is a plastic, or vice versa, or both sheets might befoil or both sheets might be plastic. Sheet 17 confines the pyrotechnic,which serves to increase its burning rate and also serves to protect thepyrotechnic from exposure until use. A master fuse 19 is provided whichpasses into the pyrotechnic layer 15 and which extends to an igniter 21.

It is obvious that the sheet 1 1 may in some configurations be omittedand the pyrotechnic 15 coated directly upon the block 5, the aft end ofthe miniature rockets 9 and the fuse ends 13. Further, with fast burningpyrotechnics and a small number of miniature rockets in the array, sheet17 may be omitted, the pyrotechnic being applied without a confiningcover sheet and yet accomplishing substantially simultaneous ignition.It is also obvious that the block 5 need not be flat on the entry orexit faces but may acquire curved surfaces whereby the rocket array maybe made to fit cylindrical, spherical or other curved envelopes.

I claim:

1. A holding, launching and ignition device for a plurality of miniaturerockets comprising in combination:

a. a block of foam plastic;

b. a plurality of holes through said plastic, said holes extending froma front surface to a rear surface of the block;

c. a miniature rocket having a nozzle at the aft end thereof in each ofsaid holes;

d. the aft end of each nozzle being substantially flush with the rearsurface of the block;

e. a fuse extending from each of the rocket nozzles and bent to lieflush on the surface of the block;

f. a thin pyrotechnic layer spread over substantially the entire rearsurface of the block;

g. said pyrotechnic layer encompassing all of the rocket fuses; and

h. means for igniting the pyrotechnic layer.

2. The device of claim 1, wherein a sheet of thin material is appliedover the pyrotechnic layer.

3. A holding, launching and ignition device for a plurality of miniaturerockets comprising in combination:

a. a block of foam plastic;

b. a plurality of holes through said plastic, said holes extending froma front surface to a rear surface of the block;

c. a layer including front and rear surfaces secured to the rear surfaceof sad block;

g. a thin pyrotechnic layer spread over substantially the entire rearsurface of the layer; h. said pyrotechnic layer encompassing all of therocket fuses; and i. means for igniting the pyrotechnic layer.

III I II I!

1. A HOLDING, LAUNCHING AND IGNITION DEVICE FOR A PLURALITY OF MINIATUREROCKETS COMPRISING IN COMBINATION: A. A BLOCK OF FOAM PLASTIC; B. APLURALITY OF HOLES THROUGH SAID PLASTIC, SAID HOLES EXTENDING FROM AFRONT SURFACE TO A REAR SURFACE OF THE BLOCK; C. A MINIATURE ROCKETHAVING A NOZZLE AT THE AFT END THEREOF IN EACH OF SAID HOLES; D. THE AFTEND OF EACH NOZZLE BEING SUBSTANTIALLY FLUSH WITH THE REAR SURFACE OFTHE BLOCK; E. A FUSE EXTENDING FROM EACH OF THE ROCKET NOZZLES AND BENTTO LIE FLUSH ON THE SURFACE OF THE BLOCK; F. A THIN PYROTECHNIC LAYERSPREAD OVER SUBSTANTIALLY THE ENTIRE REAR SURFACE OF THE BLOCK; G. SAIDPYROTECHNIC LAYER ENCOMPASSING ALL OF THE ROCKET FUSES; AND H. MEANS FORIGNITING THE PYROTECHNIC LAYER.
 2. The device of claim 1, wherein asheet of thin material is applied over the pyrotechnic layer.
 3. Aholding, launching and ignition device for a plurality of miniaturerockets comprising in combination: a. a block of foam plastic; b. aplurality of holes through said plastic, said holes extending from afront surface to a rear surface of the block; c. a layer including frontand rear surFaces secured to the rear surface of sad block; d. aminiature rocket having a nozzle at the aft end thereof in each of saidholes; e. the aft end of each nozzle being substantially flush with therear surface of the layer; f. a fuse extending from each of the rocketnozzles and bent to lie flush on the rear surface of the layer; g. athin pyrotechnic layer spread over substantially the entire rear surfaceof the layer; h. said pyrotechnic layer encompassing all of the rocketfuses; and i. means for igniting the pyrotechnic layer.